EPS块用于缓解滑坡区油气管道应变效果研究

Study on the effect of EPS block to relieve strain of oil and gas pipeline in landslide area

为响应输油气管道设计规范的要求并切实保障滑坡区管道的安全,针对管道遭受滑坡位移的受力特征提出了采用EPS块柔性材料作为管沟回填料取代回填土以缓解管道应变的防护措施。通过建立滑坡区油气管道相互作用模型,在滑坡位移载荷作用下EPS块对缓解管道应变效果显著,在同等滑坡位移条件下可以减小28%-32%的管道应变。通过进一步研究得到以下结论:①采用EPS块取代管沟回填土时可使管道的曲率半径更大、应变值更小,管道所承受的附加应变值更低;②随着EPS块初始密度的增大其缓解管道应变的能力和效果在降低,实际工程中建议选用初始密度较低的块材。EPS块厚度的选取与管径有关,选取与管径相近的厚度其缓解应变的效果最好;③采用EPS块之前应采用数值计算方法对其有效性进行评估,管道本体应变极值会明显出现在滑坡周界边缘附近,在滑坡边缘与管道交叉处设置EPS块效果较明显。

In order to respond to the requirements of code for design of gas transmission pipeline engineering,and to ensure the safety of pipelines in landslide areas,aiming at the stress characteristics of pipelines suffering from landslide displacement,we proposed a protective measure to use EPS block flexible materials as the trench backfill instead of backfill to relieve the strain of the pipeline.By establishing an oil and gas pipeline interaction model in the landslide areas,the EPS block has a significant effect on reducing the pipeline strain under the action of the landslide displacement load,and can reduce the pipeline strainby from 28%to 32%under the same landslide displacement conditions.Through further research,the main conclusions drawn in this article are as follows:First,when the EPS block is used to replace the backfill of the trench,the radius of curvature of the pipeline is larger,the strain value is smaller,and the additional strain value of the pipe is lower.Second,as the initial density of the EPS block increases,its ability and effect to relieve the strain of the pipeline are decreasing,it is recommended to use blocks with lower initial density in projects.The selection of the thickness of the EPS block is related to the pipe diameter.When the thickness of the EPS block is similar to the pipe diameter,the effect of alleviating the strain of the pipe is the best.Third,before using EPS blocks in the project,numerical calculation methods should be used to comprehensively evaluate their effectiveness.The strain extreme value of the pipeline will obviously appear near the edge of the landslide,so the effect of installing EPS blocks at the intersection of the landslide edge and the pipeline is better.